The present invention is in a process of catalytically reducing NO which is contained in a gas by means of NH.sub.3 as a reducing agent, wherein the NO-containing gas is mixed with NH.sub.3 and the mixture is reacted under normal pressure on a catalyst.
It is an object of the invention to use a catalyst which has a high NO-reducing capacity and which contains only elements which will not pollute the environment so that the catalyst when it is spent can be dumped on a waste dump without the need for special precautions.